The present invention relates generally to controlling the luminance of automotive displays and more particularly to utilizing an ambient light sensor to logically control the luminance of the displays.
Currently, when a vehicle""s headlights are activated, the cockpit displays are dimmed to lower brightness levels for improved viewing conditions. However, there are certain situations, i.e. adverse weather conditions, when the headlights may be activated during daylight, automatically dimming the displays to lower brightness thereby making the displays difficult to read.
This problem is especially apparent in high resolution, backlit displays that are used, for example, in navigation systems. Navigation systems typically have a transmissive or transreflective display that is high resolution to display a lot of detailed information. These displays are difficult to read with lower backlight brightness levels during daytime lighting conditions.
There is a need for logically determining the proper brightness level for a display depending on whether there are daytime or nighttime lighting conditions. In order to provide a useable display, it is important to detect daytime lighting conditions and over ride the commanded nighttime brightness levels that are automatically initiated upon activation of a vehicle""s headlights.
It is an object of the present invention to provide a useable display for both daytime and nighttime lighting conditions. It is another object of the present invention to logically determine and apply the correct brightness setting for a display.
It is a further object of the present invention to utilize an ambient light sensor for determining whether daytime or nighttime lighting conditions are present. It is still a further object of the present invention to control the brightness of a display using an ambient light sensor in conjunction with a dimming switch in order to override automatic dimming of display brightness.
In carrying out the above objects and other objects and features of the present invention, a method and system for detecting daytime lighting conditions and overriding a commanded nighttime brightness level for a display is necessary in order to provide a useable display. According to the system of the present invention, an ambient light sensor is used to sense the lighting condition, determine whether daytime or nighttime lighting conditions are present, and logically select the correct lighting condition for the display.
According to the method of the present invention, the display lighting conditions are sensed by an ambient light sensor. Logic is applied to the output of the light sensor to determine whether a daytime or nighttime lighting condition exists. The logic will utilize information such as whether the headlights are xe2x80x9conxe2x80x9d or xe2x80x9coffxe2x80x9d and whether daytime or nighttime lighting conditions exist, in order to adjust the display to the proper luminance level.